A wood cement board has been manufactured by a wet method, a dry method, or a semi-dry method using a reinforcing wood material and a cement as main materials. A wood flake, a wood wool, a wood pulp and the like are used as a reinforcing wood material. Nevertheless, recently wood resources show a shortage trend, and saving wood resources is requested to protect the environment of the earth.
Accordingly, to save wood resources, it is investigated to use a reinforcing wood material regenerated from a wood scrap such as used lumbers produced in dismembering wood buildings; saw-dusts and chip produced in sawing process; thinned needle-leaved trees; scrap of wood cement board and the like which have been reclaimed or burnt.
Nevertheless, as said wood scrap contains many kinds of wood it is feared that woods including a big amount of sugar as inhibiter of hardening of cement are contained in said wood scrap an d it may be very difficult to remove said wood including a big amount of sugar from said wood scrap.
Accordingly, to use practically the reinforcing wood material regenerated from said wood scrap, it may be necessary to promote a smooth hardening of cement even if said wood including a big amount of sugar is contained in said wood scrap.